diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 66b6024ba2..3a04ee1e93 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -1727,7 +1727,8 @@ void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB, SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), getCurDebugLoc(), Reg, VT); SDValue Cmp; - if (CountPopulation_64(B.Mask) == 1) { + unsigned PopCount = CountPopulation_64(B.Mask); + if (PopCount == 1) { // Testing for a single bit; just compare the shift count with what it // would need to be to shift a 1 bit in that position. Cmp = DAG.getSetCC(getCurDebugLoc(), @@ -1735,6 +1736,13 @@ void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB, ShiftOp, DAG.getConstant(CountTrailingZeros_64(B.Mask), VT), ISD::SETEQ); + } else if (PopCount == BB.Range) { + // There is only one zero bit in the range, test for it directly. + Cmp = DAG.getSetCC(getCurDebugLoc(), + TLI.getSetCCResultType(VT), + ShiftOp, + DAG.getConstant(CountTrailingOnes_64(B.Mask), VT), + ISD::SETNE); } else { // Make desired shift SDValue SwitchVal = DAG.getNode(ISD::SHL, getCurDebugLoc(), VT, |